Glass Expert Discusses Bend Test Fracture Surface

 California Failure Analysis lab performed a compound bend test to determine if the failure surface can be at an angle to the surface. One curious result was a curved fracture surface. This occurs when the clamp on the topside (i.e. tensile side) was behind the support underneath. If the two clamped sides are aligned, the crack is perpendicular to the sample face This information is useful when analyzing failures of other brittle materials such as ceramics (i.e. ceramic failure analysis).